This disclosure relates to an electric motor with a moving magnet, and an electro-acoustic transducer with such a motor.
Sealed box transducers expend a significant fraction of their total power dissipation driving the spring elements of their suspension system and the volume of air contained within their housing. Adding a spring with a negative spring constant to the transducer motor can lower the total force required to compress the spring elements of the suspension system and the air volume, and, thereby, increase transducer efficiency.